Modelling and compensation of frequency-dependent I/Q imbalance in multiple beamforming OFDM transceivers

Abstract

In this paper, we investigate the effects of asymmetric frequency-dependent joint transmit-receive I/Q imbalance on the performance of multiple beamforming MIMO OFDM systems. We derive the throughput-maximizing TX/RX beamforming coefficients taking into account I/Q imbalance effects. In addition, we propose a low-complexity pilot-aided scheme for the estimation of the channel and I/Q imbalance parameters. Our simulation results demonstrate that the proposed generalized multiple beamforming scheme is effective in mitigating I/Q imbalance effects and by using multiple beamforming data rate can be increased at the expense of increased error rate.